I can sympathize with that neighbor, because I don't care for St. Augustine. It can look good from the street, but it's coarse grass and uncomfortable to walk on. It is susceptible to bugs and diseases that Zoysia isn't. (Of course, Zoysia also has its own diseases.) I'd be disheartened if one of my neighbors changed their lawn to St. Aug, because that means it would intrude on and take over the Zoysia I've got. However, complaining to that neighbor wouldn't be worthwhile; they're free to do what they wish with their property, and there's really no feasible way to separate the two lawns.
Years ago, one of several times we moved back to Florida, we had a medium-sized dog who refused to walk on the St. Augustine. When going out into our fenced yard, the poor girl would walk within a foot of the wall where the grass was thinner, then barely go out onto the lawn to do her business. I sort of feel the same way. Don't like to do my business on a St. Augustine lawn, either.
